Garrett became head coach of the Cowboys in the 2010 season when he assumed control of the team following the sacking of Wade Phillips.

However, he struggled to guide the team to the playoffs as he finished 8-8 in his first three seasons in charge of the franchise, but his side turned the corner in the 2014 campaign as they finished with a 12-4 record to reach the post-season.

The Cowboys reached the divisional round of the playoffs before they were beaten by the Green Bay Packers, but owner Jerry Jones has still decided to reward Garrett with a five-year contract worth $30m (£19.7m), reports NFL Network.

The Cowboys have also handed extensions to defensive coordinator Rod Marinelli and Scott Linehan, promoting the latter to the position of offensive coordinator following the departure of Bill Callahan.